Method for performing single-stage cranioplasty reconstruction with a clear custom cranial implant

ABSTRACT

A method for single-stage cranioplasty reconstruction includes prefabricating a clear craniofacial implant, creating a cranial, craniofacial, and/or facial defect, positioning the clear craniofacial implant over the cranial, craniofacial, and/or facial defect, tracing cut lines on the clear craniofacial implant as it lies over the cranial, craniofacial, and/or facial defect, cutting the prefabricated clear custom craniofacial implant along the hand-marked lines for optimal fit of the clear implant within the cranial, craniofacial, and/or facial defect, and attaching the final clear craniofacial implant to the cranial, craniofacial, and/or facial defect with standard fixation methods of today.

CROSS REFERENCE TO RELATED APPLICATION

This application claims the benefit of U.S. Provisional PatentApplication Ser. No. 62/489,036, filed Apr. 24, 2017, entitled “METHODFOR PERFORMING SINGLE-STAGE CRANIOPLASTY RECONSTRUCTION WITH A CLEARCUSTOM CRANIAL IMPLANT.”

BACKGROUND OF THE INVENTION 1. Field of the Invention

The present invention generally relates to the field of surgery. Inparticular, the invention relates to the brain and skull, the art ofreconstructing skull defects (i.e., cranioplasty), neurosurgery,neurology, neuroplastic and reconstructive surgery, and craniofacialplastic surgery.

2. Description of the Related Art

Craniectomies requiring skull reconstruction (i.e., cranioplasty) areoften indicated for a multitude of etiologies including decompression(i.e., skull removal) following stroke or traumatic brain injury, boneflap infection (i.e., osteomyelitis) and/or bone flap resorptionfollowing previous neurosurgery, and/or oncological ablation for massesinvolving the underlying brain and/or skull. In the setting of traumaticbrain injuries with cerebral edema, stroke (i.e., brain ischemia) withbleeding, and/or autologous bone flap resorption or osteomyeliticinfections requiring removal, delayed cranioplasties are necessary at asecondary stage.

In fact, nearly 250,000 primary brain tumors/skull-based neoplasms arediagnosed each year resulting in a range of 4,500-5,000 second-stageimplant cranioplasties per year (Berli J U, et al., “ImmediateSingle-Stage Cranioplasty Following Calvarial Resection for Benign andMalignant Skull Neoplasms Using Customized Craniofacial Implants,” TheJournal of Craniofacial Surgery, Vol. 26, No. 5, September 2015).

The common types of cranial implants used today, in instances where theexact bone defect shape and size is known well in advance, are made mostoften from a variety of safe biomaterials (i.e. manmade), includingtitanium mesh, porous hydroxyapatite (HA), polymethylmethacrylate(PMMA), porous polyethylene, and polyether-ether-ketone (PEEK), amongothers. Of note, the most common “off-the-shelf” solution used byneurosurgeons and reconstructive surgeons is titanium mesh implants bentto serve as a “bridge”—simply spanning the skull defect from one side toanother to create a non-specific curvature and protection barrier forthe brain. The thin titanium mesh (which is 1 millimeter thick versusthe normal skull thickness of 4-5 millimeters) accompanies severaldrawbacks and limitations including 1) non-anatomical thickness andsecondary dead-space underneath, 2) a need to overlap neighboring skullareas for bridging and stability which can lead to visible deformitiesand scalp irregularities within the anterior craniofacial regions (i.e.,non-hair bearing regions), and 3) a high risk of extrusion through thescalp when placed under thin and/or irradiated scalps.

A distinct subset of skull reconstruction patients includes craniectomydefects following oncological resection of calvarial lesions and/orbrain tumors invading the skull. For this type of tumor ablativesurgery, where tumors and/or processes (i.e., radiation therapy) involvethe skull, cranioplasties to date have previously been performed usingeither 1) suboptimal hand-molding techniques with “off-the-shelf”products” or 2) a delayed, second surgery allowing the design andfabrication of a customized cranial implant. Now, with the advent ofcomputer-aided design/manufacturing (CAD/CAM) and customizedcraniofacial implants, more suited alternatives are becoming widelyavailable and have been published (Berli J U, et al., “ImmediateSingle-Stage Cranioplasty Following Calvarial Resection for Benign andMalignant Skull Neoplasms Using Customized Craniofacial Implants,” TheJournal of Craniofacial Surgery, Vol. 26, No. 5, September 2015).

Using CAD/CAM fabrication, near-perfectly shaped custom cranial implantscan be ordered and pre-fabricated with exact patient-specific curvaturesto an oversized dimension, and then modified around the edgesintra-operatively for an exact fit following bone/brain tumor resectionas described by Gordon et al. (See, Gordon C R, et al., “Discussion ofUsefulness of an Osteotomy Template for Skull Tumorectomy andSimultaneous Skull Reconstruction,” The Journal of Craniofacial Surgery,Vol. 27, No. 6, September 2016; Berli J U, et al., “ImmediateSingle-Stage Cranioplasty Following Calvarial Resection for Benign andMalignant Skull Neoplasms Using Customized Craniofacial Implants,” TheJournal of Craniofacial Surgery, Vol. 26, No. 5, September 2015.)

To accomplish this approach, preoperative imaging such as computedtomography (CT) is used ahead-of-time to identify the patient's exactskull and brain anatomy and the patient's exact skull curvature (sinceall patients have different curvatures based on region, gender, andage). However, the exact cranial defect size (following oncologicalresection) is truly unknown until the final tumor and local diseaseextension are removed to completion with visual confirmation—since insome instances, there is tumor extension into neighboring regions (i.e.,bone, brain) unseen on pre-operative imaging which then requires a moreextensive resection than originally planned. As such, for one to followtrue oncological principles and to make sure the surgeon is unrestrictedin removing all concerning areas of disease (thereby decreasing all riskof recurrence), the prefabricated custom implant must be designed withextraneous material around the edges—to be able to accommodate theunexpected tumor size and whether or not a larger size is needed, asopposed to what was originally imagined. Therefore, the pre-operative CTscan images are used to virtually plan the surgical skull cuts in anoversized fashion around the bone/brain tumor with excess of severalinches (up to 5 to 7 centimeters, on average, of excess implantmaterial) based on the tumor's exact location (and to allow thegeometric design of the three-dimensional (3D) custom cranial implant tobe created in an “oversized fashion”). But as opposed to the current“off-the-shelf” products mentioned previously, this customized implantmade of a safe biomaterial remains advantageous since it's“patient-specific” with respect to the individual's exact craniofacialconvexity and curvature equating to minimal-to-no deformity aftersurgery.

In summary, the “single-stage cranioplasty” method and pre-fabricatedcustom implant with excess dimensions, described here, is designed toaccount for any additional bone/soft tissue loss that may becomenecessary to remove during the surgery (that is, due to unanticipatedlocal brain or skull invasion, desire to decrease risk of recurrence andenlargement of resection limits, an unknown tumor pathology grade untilresected and sent for frozen analysis with pathology, etc.). Therefore,after resecting the bony/soft tissue region of interest, the surgeon isforced to shave down and modify the oversized custom cranial implant tofit exactly within the resected area using artistic hand-eyecoordination, dedicate significant time and labor intra-operatively (upto 80 minutes), and work back and forth in the operating room betweenthe patient's final anatomy and a sterile back table to achieve an idealfit, as described by Berli J U, et al. (“Immediate Single-StageCranioplasty Following Calvarial Resection for Benign and MalignantSkull Neoplasms Using Customized Craniofacial Implants,” The Journal ofCraniofacial Surgery, Vol. 26, No. 5, September 2015). Similarly, asurgeon could remove normal bone in order to place an intercranialdevice above an area of brain pathology amenable to local intervention,as described by Gordon et al. in International Patent ApplicationPCT/US2016/030447, filed May 2, 2017, entitled “LOW PROFILE INTERCRANIALDEVICE,” (published as WO 2017/039762) (762 Publication), which isincorporated herein by reference.

As such, current techniques for modifying the oversized custom cranialimplant for “single-stage cranioplasty” are inefficient and far fromoptimal given the abundant amount of time and artistic labor needed toperform “back-and-forth” size modification with a handheld burr. Withsignificant operative times being extended, the patient's peri-operativemorbidity is increased as well as are the fixed operating rooms costssurrounding prolonged surgery. Therefore, newer strategies have beendeveloped and described for instance using “opaque” customized implants,such as disclosed in the inventor's own U.S. Patent ApplicationPublication No. 2017/0000505, entitled “Computer-AssistedCraniomaxillofacial Surgery.”

Still further, the current market only offers these opaque (ornon-clear) cranial implants (described in U.S. Patent ApplicationPublication No. 2017/0000505) with zero visibility and zerotranslucency—which is a significant deterrent to the neurosurgeon orreconstructive craniofacial surgeon hoping to perform single-stagecranioplasty. With the abundant availability of only “opaque” implants,on the current market, there is increased complexity and artistic demandchallenging all surgeons when faced with this difficult scenario. Thesedemands are demonstrated in FIGS. 1A-G which show a cranioplastyperformed with an opaque cranial implant. As the pictures show, theprocedure requires hand-modification following skull tumor resection,and its difficulty is exponentially increased. The hand modification ishighly difficult due to the inability to see through the implant and NOTbeing able to appreciate the underlying skull margins underneath whenplaced in-situ. Of note, one can appreciate the unintentional perimeterdefects secondary to one's ability to not see clearly through theimplant—which is related to either “undershaving” or “overshaving” theimplant's borders—as a way to make the oversized implant fit. However,undershaving leaves the implant too small and increases risk forresulting deformity. But in an ideal setting, a “clear” customizedcranial implant (made of a safe biomaterial with complete translucency)would be a much welcomed advance to the fields of neurosurgery and skullreconstruction—both to lower accompanying complexity and to drasticallyquicken the operation.

Accordingly, a surgical method that allows surgeons to resize, adjust,modify or trim alloplastic or bio-engineered cranial implants duringcranioplasty (i.e., skull reconstruction) surgery to fit the surgicalcuts, defects, and/or preexisting deformities in a streamlined fashionwith reduced complexity, operative time, and/or demand for artistichand-eye coordination, or generally overcome the limitations of currenttechnology and surgical methods, described here, would be welcome in theart. While Gordon et al. have previously developed surgical method,techniques and systems using a robot-assisted and/or laser-assistedmethod as described in U.S. Patent Application Publication No.2017/0000505, these novel technologies were developed solely based onthe assumption that one would be forced to use the commonly-available,“opaque” customized cranial implants. Thus, up until this time, therehave been no developments taking advantage of specific implantbiomaterials that are clear and/or newfound implant translucency in themanner disclosed and claimed in accordance with the present invention.

SUMMARY OF THE INVENTION

It is, therefore, an object of the present invention to provide a methodfor cranioplasty. The method includes first prefabricating a clearcraniofacial implant with complete transparency and clarity based uponinformation generated by preoperative scans. The method also includescreating a cranial, craniofacial, and/or facial defect, and positioningthe clear craniofacial implant over the cranial, craniofacial, and/orfacial defect. Thereafter, cut lines are traced by hand on the clearcraniofacial implant (since one can see the bony edges of the cranial,craniofacial and/or facial defect through the clear craniofacialimplant) as it lies over the cranial, craniofacial, and/or facialdefect, wherein a boundary of the cranial, craniofacial, and/or facialdefect is easily viewable through the clear craniofacial implant as aresult of the clear construction of the craniofacial implant. The clearcustom craniofacial implant is cut along the traced cut lines drawn byhand for optimal fit of the craniofacial implant along the cranial,craniofacial, and/or facial defect and to create a final clearcraniofacial implant with exact fit. The final clear craniofacialimplant is attached to the cranial, craniofacial, and/or facial defect.This procedure would not be possible in the setting of a standard,“opaque” implant.

It is also an object of the present invention to provide a method forcranioplasty wherein the clear craniofacial implant is composed of PMMA.

It is further an object of the present invention to provide a method forcranioplasty including the step of positioning the clear craniofacialimplant over the cranial, craniofacial, and/or facial defect prior tothe step of tracing cut lines.

It is another object of the present invention to provide a method forcranioplasty wherein the step of positioning includes placing the clearcraniofacial implant over the cranial, craniofacial, and/or facialdefect in a desired orientation based upon a unique anatomy of an outersurface of a skull surrounding the cranial, craniofacial, and/or facialdefect.

It is a further object of the present invention to provide a method forcranioplasty wherein the step of tracing includes tracing a periphery ofthe cranial, craniofacial, and/or facial defect directly onto the clearcranio facial implant using a sterile intra-operative marking pen bybeing able to see through the clear craniofacial implant while“in-site”.

It is another object of the present invention to provide a method forcranioplasty wherein the step of positioning includes placing the clearcraniofacial implant over the cranial, craniofacial, and/or facialdefect in a desired orientation based upon a unique anatomy of an outersurface of a skull surrounding the cranial, craniofacial, and/or facialdefect which is visible through the clear craniofacial implant.

It is also an object of the present invention to provide a method forcranioplasty wherein the step of cutting includes trimming the clearcraniofacial implant using medical grade tools, computer-assisted,and/or robot-assisted devices in an operating room along boundariesdefined by the traced cut lines.

It is another object of the present invention to provide a method forcranioplasty including the steps of identifying a diseased portionassociated with aberrant craniofacial and/or brain anatomy andgenerating a computer-readable reconstruction of a patient's anatomyassociated with the diseased portion for the purpose of designing andfabricating the clear craniofacial implant, or to provide a method ofplacing intercranial device as described in the '762 Publication over anarea of brain pathology amenable to local intervention (i.e., byremoving normal bone).

It is also an object of the present invention to provide a method forcranioplasty wherein the step of creating a cranial, craniofacial,and/or facial defect includes cutting out a portion of a skull to bereplaced with the clear craniofacial implant.

It is another object of the present invention to provide a method forcranioplasty wherein a neurological device, for example, as described inthe '762 Publication, with constant or intermittent function isincorporated within the clear craniofacial implant.

It is a further object of the present invention to provide a method forcranioplasty wherein the neurological device is a monitoring device ordevice for treating a neurological disorder.

It is also an object of the present invention to provide a method forcranioplasty wherein the cranioplasty is a single-stage cranioplasty.

It is another object of the present invention to provide a method forcranioplasty wherein the clear craniofacial implant includes an etchingor a marking.

It is further an object of the present invention to provide a method forcranioplasty wherein the etching or marking indicates a desiredimplanted orientation of the clear craniofacial implant.

It is also an object of the present invention to provide a method forcranioplasty wherein the etching or marking identifies anatomy beneaththe defect, a tumor sight, an aneurysm location, or a functionalcomponent (i.e., brain pathology).

It is another object of the present invention to provide a method forcranioplasty wherein the etching or marking identifies a prescription, adisease state, or a date of surgery, or type of implantableneurotechnology housed within the clear craniofacial implant.

It is another object of the present invention to provide a method forcranioplasty wherein the step of creating a cranial, craniofacial,and/or facial defect includes cutting out a portion of a skull to bereplaced with the clear craniofacial implant in instances where anintercranial device as described in the '762 publication would bevaluable to the neurosurgical patient.

It is a further object of the present invention to provide a method forcranioplasty wherein a neurological device is incorporated within theclear craniofacial implant in an effort to reduce visible deformityand/or pressure on the scalp risking extrusion.

It is also an object of the present invention to provide a method forcranioplasty wherein the neurological device is a monitoring device ordevice for treating a neurological disorder, hydrocephalus shuntingdevice with pressure monitor, or direct medicine delivery device.

It is another object of the present invention to provide a method forcranioplasty wherein the cranioplasty is a single-stage cranioplasty,meaning that the skull defect dimensions are unknown prior to surgery.

It is also an object of the present invention to provide a method forcranioplasty wherein the etching(s) or marking(s) indicate a desiredimplanted orientation of the clear craniofacial implant based on itsrelation to the brain anatomy underneath.

Other objects and advantages of the present invention will becomeapparent from the following detailed description when viewed inconjunction with the accompanying drawings, which set forth certainembodiments of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A-G show a cranioplasty performed with an opaque cranial implant.

FIGS. 2A-2F, 3A, and 3B illustrate together a schematic representativeof the present method for single-stage cranioplasty reconstruction usinga clear craniofacial implant and the final result with the embeddedfinal clear craniofacial implant, wherein FIGS. 2A-2F show the stepsfrom a single-stage cranioplasty reconstruction in accordance with thepresent invention and FIGS. 3A and 3B respectively show pre-operative(left) and post-operative (right) CT scans showing a large left sidedskull tumor and post-resection views exhibiting ideal symmetry andoptimal implant location using a clear custom cranial implant inaccordance with the present invention.

In particular, FIG. 2A shows cutting out the diseased portion of theskull or that portion of the skull required to access diseased tissue ofthe brain or other portion of the anatomy, and thereby creating acranial, craniofacial, and/or facial defect.

In particular, FIG. 2B shows a perspective view and a top plan view ofthe removed portion of the skull.

In particular, FIG. 2C shows positioning the prefabricated clear customcraniofacial implant over the cranial, craniofacial, and/or facialdefect created by the removal of the diseased anatomical feature.

In particular, FIG. 2D shows tracing cut lines with a hand-held sterilemarker on the prefabricated clear custom craniofacial implant as it liesin-situ over the cranial, cranio facial, and/or facial defect.

In particular, FIG. 2E shows cutting the prefabricated clear customcraniofacial implant along the tracing cut lines for optimal fit of theprefabricated clear custom craniofacial implant along the cranial,craniofacial, and/or facial defect and to create the final-size/shape ofclear craniofacial implant for exact fit.

In particular, FIG. 2F shows attaching the final clear craniofacialimplant to the patient.

In particular, FIG. 3A is a pre-operative CT scan.

In particular, FIG. 3B is a post-operative CT scan.

FIG. 4 is a perspective view of an alternate cranial implant inaccordance with the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The detailed embodiments of the present invention are disclosed herein.It should be understood, however, that the disclosed embodiments aremerely exemplary of the invention, which may be embodied in variousforms. Therefore, the details disclosed herein are not to be interpretedas limiting, but merely as a basis for teaching one skilled in the arthow to make and/or use the invention.

Referring to FIGS. 2A-2F, 3A, 3B, and 4, the present invention relatesto a novel method for performing single-stage cranioplasty with “clear”customized implants (see for example, FIGS. 2C and 2D showing the clearcustom craniofacial implant 10 held directly above a skull tumor defectfollowing extirpation (that is, the cranial, craniofacial, and/or facialdefect 100 as discussed below) prior to single-stage modification). Asexplained above in the Background of the Invention, the method of“single-stage cranioplasty” is defined as a surgery where the surgeonintends to create a complicated, full-thickness, three-dimensionaldefect in the craniofacial skeleton in real-time and then replace thesubsequent craniofacial bone (and/or soft tissue) with an oversizedpatient-specific custom implant requiring on-table sizemodification—versus using an “off-the-shelf” biomaterial with no form ofcustomization specific to the patient's anatomy. Or, this could beapplicable to situations when the surgeon is notified of an upcomingcase with little notice and does not have time to obtain other types ofskull implants which may take more time to manufacture, like those madeof porous polyethylene, for example. Furthermore, clear implants forsingle-stage cranioplasty also accompany a significant advantage ofseeing the brain anatomy underneath during the case which allows forcritical viewing of potential bleeding sources, such as the tumor cavityor sagittal sinus, for example. As such, this novel “translucency” ofthe clear custom craniofacial implant 10 equates to both a safer, andmore effective, method for single-stage cranioplasty.

In accordance with the present invention, and as will be explained belowin greater detail, the present invention makes use of prefabricatedcustom craniofacial implants 10 made of a “clear” translucent material,man-made alloplastic or other tissue engineered material, to allow andimprove a surgeon's ability to view a cranial, craniofacial, and/orfacial defect 100, and brain anatomy distal (i.e., underneath) to theprefabricated clear custom craniofacial implant 10 when placed into anoverlapping position (see FIGS. 2A-2F, 3A, and 3B showing a single-stagecranioplasty reconstruction in accordance with the present invention)relative to the cranial, craniofacial and/or cranial defect 100. Inaccordance with the single-stage cranioplasty reconstruction shown inFIGS. 2A-2F, 3A, and 3B involving a large skull tumor and clear customimplant 10 the two distinct advantages of the present invention aredepicted—one being streamlined customization, and the other beingcritical viewing of brain-related structures for potential bleeding riskduring the case.

Of note, one can appreciate the minimal perimeter defects seen at timeof inset following intra-operative size modification of a “clear”customized craniofacial implant 10—which required only 8 total minutesfor real-time, size modification. The reduced time and final outcome iscompletely related to the enhanced value of the implant's cleartranslucency—and the required time is about 90% less when compared tothe previous cases described by the inventor's team in instances ofusing an opaque implant. By allowing the surgeon to see through theprefabricated “clear” custom cranio facial implant 10 and directly viewthe cranial, cranio facial, and/or facial defect 100 and brain anatomyover which the craniofacial implant 10 is to be positioned, the surgeoncan save significant time and effort in matching the cranial,craniofacial, and/or facial defect 100 directly to the prefabricatedclear custom craniofacial implant 10, without the use of multipleestimations or templates. Seeing through the clear custom craniofacialimplant 10 also allows the surgeon to choose where to reshape theprefabricated clear custom craniofacial implant 10 and form the finalclear craniofacial implant 10′ that will ideally fit the cranial,craniofacial, and/or facial defect 100. This newfound advantage ofcomplete clarity and enhanced visibility through the craniofacialimplant 10 described herein provides several unprecedented advantagesspecific to “single-stage cranioplasty,” including 1) ease-of-use withdrastic reduction in operative times, 2) a new found ability to providereal-time visibility to pertinent anatomy underneath like exact boneedge dimensions dictating implant size modification, 3) the potential todiscover brain-related bleeding underneath which requires electrocauteryand can help to prevent re-operations related to post-operativebleeding, and 4) visualize periodic dural pulsations suggestive ofhealthy brain parameters. As such, this invention drastically reducesthe time needed for reshaping and matching the prefabricated clearcustom craniofacial implant 10 by around ten-fold, which now rangesbetween 8 and 10 minutes in some instances performed by the inventor,Dr. Gordon (instead of up to 80 minutes, as reported by Berli et al, JCraniofacial Surgery Vol. 26, No. 5, September 2015).

As those skilled in the art will appreciate, and as mentioned above,prefabricated custom craniofacial implants manufactured forreconstruction are inherently larger than the cranial, craniofacial,and/or facial defect created during surgery to adequately fill thecranial, craniofacial, and/or facial defect. In accordance with apreferred embodiment of the present invention, the clear customcraniofacial implant 10 with full transparency is a prefabricatedimplant such as a 3rd-party sourced alloplastic or tissue-engineeredimplant, preferably manufactured from clear poly(methyl methacrylate)(PMMA) or any other clear biocompatible material suited for safe use incraniofacial reconstruction. While a clear PMMA craniofacial implant isused in accordance with a preferred embodiment as discussed herein, itis appreciated the prefabricated clear custom craniofacial implant 10may include a polymer, metal, bioengineered material, or anycombinations thereof for which may also be clear. For example, theprefabricated clear custom craniofacial implant 10 may include anybiomaterial that may allow enhanced visibility with completetranslucency. In addition, it is appreciated the use of the term craniofacial implant herein is intended to include all clear implants that maybe used in conjunction with skull reconstruction procedures, facialreconstruction, or any combination thereof. Regardless of the materialconstruction employed in the fabrication of the clear prefabricatedcustom craniofacial implant, the implant must be completely translucentto provide the advantages described herein, which include 1) decreasedoperative times since underlying anatomy is assessed in superimposedfashion, 2) decreased blood loss for patient since the implantreconstruction is completed much faster, 3) decreased anesthesia andoperative times, 4) decreased costs to hospital since surgery isabbreviated, and 5) reduced demand for artistic, hand-eye coordination,additional labor and/or work effort provided by the reconstructivesurgeon. As used herein the term “clear” is intended to refer to amaterial that is substantially completely transparent (for example, thecraniofacial implant is completely transparent with the exception of aneurological device(s) that might be integrated into the craniofacialimplant and which does not otherwise impede the ability to achieve theunderlying principles of the invention) and exhibits the property oftransmitting rays of light through its substance so that bodies situatedbeyond or behind can be distinctly seen when looking through thematerial.

In addition to the direct advantages associated with the single-stagecranioplasty reconstruction, the craniofacial implant being“translucent” also allows for real-time transmission of light, which iscritical for future applications related to any and all battery-powered,low-profile intercranial devices capable of neuromodulation (i.e.implanted functional RNS systems like NeuroPace) and capable of sendingwireless electrocorticography (ECoG) signals for data collection,interpretation, treatment, and intervention; and a multitude of otherwavelength-related mediums like optical coherence tomography (OCT)imaging and ultrasound imaging—as described by Gordon et al inInternational Patent Application PCT/US2016/030447, filed May 2, 2016entitled “LOW PROFILE INTERCRANIAL DEVICE” (published as WO2017/039762), and U.S. patent application Ser. No. 15/669,268, filedAug. 4, 2017, entitled “METHOD FOR MANUFACTURING A LOW-PROFILEINTERCRANIAL DEVICE AND THE LOW-PROFILE INTERCRANIAL DEVICE MANUFACTUREDTHEREBY” (published as U.S. Patent Application Publication No.2018/0055640), which claims the benefit of U.S. Provisional PatentApplication 62/381,242, filed Aug. 30, 2016, entitled “METHOD FORMANUFACTURING A LOW-PROFILE INTERCRANIAL DEVICE AND THE LOW-PROFILEINTERCRANIAL DEVICE MANUFACTURED THEREBY,” all of which are incorporatedherein by reference. In addition, Dr. Gordon and team published a “firstin-human” experience article related to this novel invention (Gordon C,et al, “First In-human experience with complete integration ofneuromodulation device within a customized cranial implant,” OperativeNeurosurgery 2017; 10 (6): 1-7).

As those skilled in the art will appreciate single-stage implantcranioplasty involves the surgical rebuilding and/or reconstruction ofportions of the craniomaxillofacial skeleton to correct deformities(e.g., following trauma) and/or defects with unanticipated dimensionscreated in real-time—such as those involving tumor extirpation.Preoperative imaging such as CT or MRI identifies the patient anatomy.The surgery is planned using virtual pre-operative imaging to helpidentify an area of disease (e.g., the tumor) requiring resection andreconstruction. In addition to identifying diseased portions of thecraniofacial anatomy, diseased portions of the brain anatomy may beidentified and addressed in the implantation of an intercranialdevice(s) including neurotechnology 20 with constant or intermittentfunction as described in the '762 Publication (see, for example, FIG. 4)wherein the intercranial device is substantially clear and functions inthe same manner as the clear custom craniofacial implant 10 describedherein. Such neurological devices 20 include, but are not limited to,hydrocephalus shunt valve/pressure monitor, direct medicine deliverydevice, microchip polymer delivery device, radiation therapy device,functional neuromodulation device, etc. Bony cuts are planned and theprefabricated clear custom craniofacial implant 10 is designed to fitinto the resected region following planned modification of theprefabricated clear custom craniofacial implant 10 (that is, thecreation of the final clear craniofacial implant 10′). See, for example,FIG. 2F showing the clear custom craniofacial implant with ideal fit inplace following tumor resection and optimal reconstruction, and withminimal gaps along skull-implant interface.

Still further, and considering the vast array of neurosurgicaltechniques and neurological devices that might be used in conjunctionwith the methodology underlying the present invention, the clear customcraniofacial implant may be manufactured to allow for the transmissionof waves other than optical light waves, for example, the clear customcraniofacial implant may be sonolucent (that is, allowing passage ofultrasonic waves without production of echoes that are due to reflectionof some of the waves) or radiolucent (that is, allowing passage of radiowaves without production of echoes that are due to reflection of some ofthe waves). By way of example, the clear custom craniofacial implant 10may be manufactured in a manner allowing for the transmission ofultrasonic waves as described in U.S. Pat. No. 9,044,195, entitled“IMPLANTABLE SONIC WINDOW,” ('195 Patent) which is incorporated hereinby reference. As explained in the '195 Patent, a strong, poroussonically translucent material through which ultrasonic waves can passfor purposes of imaging the brain is employed, wherein the material is apolymeric material, such as polyethylene, polystyrene, acrylic, orpoly(methyl methacrylate) (PMMA). In addition, U.S. Pat. No. 9,535,192,entitled “METHOD OF MAKING WAVEGUIDE-LIKE STRUCTURES,” ('192Publication) and U.S. Patent Application Publication No. 2017/0156596,entitled “CRANIAL IMPLANTS FOR LASER IMAGING AND THERAPY,” ('596Publication) both of which are incorporated herein by reference, makingwaveguide-like structures within optically transparent materials usingfemtosecond laser pulses wherein the optically transparent materials areexpressly used in the manufacture of cranial implants. The '596publication explains the use of optically transparent cranial implantsand procedures using the implants for the delivery of laser light intoshallow and/or deep brain tissue. The administration of the laser lightcan be used on demand, thus allowing real-time and highly precisevisualization and treatment of various pathologies. Further still,Tobias et al. describe an ultrasound window to perform scanned, focusedultrasound hyperthermia treatments of brain tumors. Tobias et al.,“ULTRASOUND WINDOW TO PERFORM SCANNED, FOCUSED ULTRASOUND HYPERTHERMIATREATMENTS OF BRAIN TUMORS,” Med. Phys. 14(2), March/April 1987,228-234, which is incorporated herein by reference. Tobias et al. testedvarious materials to determine which material would best serve as anacoustical window in the skull and ultimately determined polyethylenetransmitted a larger percentage of power than other plastics and wouldlikely function well as an ultrasonic window. Further still, Fuller etal., “REAL TIME IMAGING WITH THE SONIC WINDOW: A POCKET-SIZED, C-SCAN,MEDICAL ULTRASOUND DEVICE,” IEEE International Ultrasonics SymposiumProceedings, 2009, 196-199, which is incorporated herein by reference,provides further information regarding sonic windows.

Radiolucency as applied to the present invention allows a clinician tosee the anatomy surrounding the clear custom craniofacial implant 10without “scatter” or interfering artifacts from the implant fordiagnosis and follow-up. By another definition of radiolucency, radiowaves are able to transmit easily through the clear custom craniofacialimplant 10, for example, via Bluetooth or other frequency transmission;which can serve many purposes including, but not limited to, datamanagement and controller telemetry. The provision of radiolucency alsoallows for the integration of markings (as discussed below) made withradiographic materials, for example, barium sulfate, to be visible incontrast to the remainder of the craniofacial implant to allow forunique device identifiers or unique patient information to be visible onpost-operative scans.

Considering the provision of optical lucency in the present clear customcraniofacial implant 10, the ability to optically transmit through theclear custom craniofacial implant 10 allows for visualization of anatomydistal to the clear custom craniofacial implant 10 (as previouslydescribed), allows for the potential of higher bandwidth optical links(similar to radio transmission) between proximal adjunct devices, allowsfor light to be emitted from the clear custom craniofacial implant 10 toadjacent anatomy which could aid in optogenetics, and allows forimaging/therapeutic modalities that rely on light like optical coherencetomography from within the implant

In the newly described form of single-stage cranioplasty in accordancewith the present invention, prior to surgery the prefabricated clearcustom craniofacial implant 10 is ordered and delivered with oversizeddimensions (several extra inches of material along the periphery) toaccount for additional bone or soft tissue that may be removed and needsto be replaced during the operation—and to, therefore, allow fortrimming that is often necessary to optimize fit. After resecting thebony skull region of interest, the surgeon shaves down the oversized,prefabricated clear custom craniofacial implant 10 with a handheld burrto form the final clear craniofacial implant 10′ that will have an exactfit within the resected area (that is, the cranial, craniofacial, and/orfacial defect 100).

As will be appreciated based upon the following disclosure, the presentmethod may be used for surgical repair of all cranial, craniofacial,and/or facial defects requiring large-size cranioplasty (e.g., >25square centimeters). For example, embodiments described herein may beused for designing, forming, modifying and/or implanting clear customcraniofacial implants following benign/malignant skull neoplasm (tumor)resection or any form of bone disease requiring resection and visibilityto pertinent anatomy underneath. Further, it is contemplated the presentmethod may be used in order to implant an intercranial device, forexample, as disclosed in the '762 Publication, above an area of brainpathology amenable to local intervention by the neurotechnology housedwithin the implant. Such an implantation of the present method wouldlikely involve the removal of normal bone as opposed to diseased bone.

The present method provides for enhanced visualization related to atumor, bone edges left behind, dura, brain pulsation, and any potentialbleeding sources. The present invention further provides for enhancedvisualization of the cranial, craniofacial, and/or facial defect 100resulting from the removal of a portion of the skull to access the brain(or other tissue), and the reshaped final clear craniofacial implant 10′for exact positioning in place within the full-thickness defect of theskull. In other words, through the novel use of “clear” craniofacialimplants in accordance with the present invention, the intraoperativeexecution of single-stage implant cranioplasties is improved andenhanced for ideal patient safety, streamlined execution with less timeand effort, and reduced patient morbidity related to prolonged operativetimes. Furthermore, clear implants, such as those described here,contain all the necessary benefits for various implantableneurotechnologies such as neuromodulators, brain medicine delivery,hydrocephalus shunt valves, etc.

In practice, the method of the present invention includes the followingsteps: a) identifying a diseased portion associated with thecraniofacial anatomy; b) generating and/or accessing a computer-readablereconstruction of a patient's anatomy, such as via a preoperative CTscan that includes an anatomical feature, such as a cranial,craniofacial, and/or facial defect, and constructing a 3D model of theanatomy (see FIG. 3A); c) preselecting a resection area on the model; d)determining implant dimensions (can be a few inches greater than thesize of the cranial, craniofacial, and/or facial defect) andprefabricating the clear custom craniofacial implant 10 based uponinformation generated by preoperative scans (see the prefabricating theclear custom craniofacial implant 10 as shown in FIG. 2C); e) cuttingout the diseased portion of the skull or that portion of the skullrequired to access diseased tissue of the brain or other portion of theanatomy, and thereby creating a cranial, craniofacial, and/or facialdefect 100 (see FIGS. 2A and 2B); f) removing the diseased anatomicalfeature (in addition to step (e), if further necessary); g) positioningthe prefabricated clear custom craniofacial implant 10 over the cranial,craniofacial, and/or facial defect 100 created by the removal of thediseased anatomical feature (see FIG. 2C); h) tracing cut lines 12 witha hand-held sterile marker on the prefabricated clear customcraniofacial implant 10 as it lies in-situ over the cranial,craniofacial, and/or facial defect 100 (this advantage being permittedas a result of the clear construction of the craniofacial implant 10used in accordance with the present invention (see FIG. 2D)); i) cuttingthe prefabricated clear custom craniofacial implant 10 along the tracingcut lines 12 for optimal fit of the prefabricated clear customcraniofacial implant 10 along the cranial, craniofacial, and/or facialdefect 100 and to create the final-size/shape of clear craniofacialimplant 10′ for exact fit (see FIG. 2E); j) attaching the final clearcraniofacial implant 10′ to the patient 102 (see FIG. 3F); k) obtaininga post-operative image of the patient 102 and the attached final clearcraniofacial implant 10′, such as via a CT scan (see FIGS. 3A and 3Brespectively showing a pre-operative and post-operative CT scans showinglarge left sided skull tumor and post-resection views showing idealsymmetry and optimal implant location using a clear custom craniofacialimplant). Of note, and with reference to FIGS. 3A and 3B, one can seethat the bone defect ended up being much larger in size as compared towhat one visualizes on pre-operative CT scan—and thus the need for thesingle-stage cranioplasty method being described here.

With the exception of steps (g), (h) and (i), the steps associated withthe present invention are conventional and variations may be made inaccordance with surgical preferences and advancements in medicine. Assuch, and with reference to FIGS. 2C-2F these steps are described infurther detail below. After removing the diseased anatomical feature,the prefabricated clear custom craniofacial implant 10 is prepared forattachment near the healthy portions of the patient's anatomy. Inparticular, and with the cranial, craniofacial, and/or facial defect 100open, the surgeon will retrieve the prefabricated clear customcraniofacial implant 10. Based upon, and in consideration of, the uniqueanatomy of the full-thickness defect within the skull 106 and the outersurface of the skull 106 surrounding the cranial, cranio facial, and/orfacial defect 100, the surgeon places the prefabricated clear customcraniofacial implant 10 over and within the space defined by thecranial, cranio facial, and/or facial defect 100 in a desiredorientation. Because the prefabricated custom craniofacial implant 10 is“clear”, the surgeon is now able (unlike before with thecommonly-available, “opaque” implants) to view the periphery 108 of thedefect 100 through the prefabricated clear custom craniofacial implant10 in real-time and uses a sterile intra-operative marking device (forexample, a marking pen) 60 to trace the periphery of the cranial,craniofacial, and/or facial defect 100 directly onto the prefabricatedclear custom craniofacial implant 10—as opposed to the current daypractice of using a hand-made template or cutting guide. While tracingwith a marking device is disclosed in accordance with a preferredembodiment, it is appreciated the creation of the tracing cut lines maybe achieved via various other mechanisms for example, etching orotherwise marking the implant.

The surgeon then trims the prefabricated clear custom craniofacialimplant 10 along the tracing cut line 12 with an intraoperative contourdrill 50. Trimming is achieved using various medical grade tools wellknown to those skilled in the art, and it is appreciated surgeons willuse various trimming techniques depending upon their preferences. Oncethe prefabricated clear custom craniofacial implant 10 is fully trimmedand has become the final clear craniofacial implant 10′, the final clearcraniofacial implant 10′ is secured to the skull 106 using techniqueswell known to those skilled in the art providing durable fixation.

The present method exponentially reduces the time necessary for sizingthe prefabricated clear custom craniofacial implant 10 relative to theremoved bone. The method relies on the use of a fully translucent andclear craniofacial implant 10 and associated techniques for matching theclear craniofacial implant 10 to the cranial, craniofacial, and/orfacial defect 100. As described above, single-stage cranioplasties areperformed to reconstruct large defects in the skull following removal ofunanticipated amounts of cranial bone and/or soft tissue. With this inmind, the present method may be used for reconstructing all craniofacialdefects with clear craniofacial implants for an ideal result unlike everbefore with improved patient satisfaction, reduced morbidity, lessenedrisk for bleeding, reduced operating room costs, and enhanced patientsafety. Accordingly, the present method may be used by all surgeons inperforming single-stage cranioplasty following resection of bone diseasefor which the exact defect size is unknown in advance.

As shown with reference to FIG. 4, and as discussed above, variousneurological devices 20, for example, monitoring and treatment devices,such as remote pressure monitor, may also be incorporated within thisnovel clear implant and are safe from injury during size modificationsolely due to the translucency and enhanced visibility provided by theclear custom cranio facial implant. The neurological devicesincorporated within the clear implant may provide visual monitoring forpotential tumor recurrence (i.e., ultrasound, OCT (Optical CoherenceTomography)), may provide battery-powered treatment options for epilepsy(i.e., NeuroPace RNS system), Alzheimer's, or Parkinson's withelectricity and/or battery-powered medicinal delivery options withoncological methods such as convection enhanced delivery (CED) and localmedicine delivery. Such abilities are preferably achieved usinginnovative modalities disclosed by Gordon et al. in International PatentApplication PCT/US2016/030447, filed May 2, 2017, entitled “LOW PROFILEINTERCRANIAL DEVICE,” (published as WO 2017/039762), and U.S. patentapplication Ser. No. 15/669,268, filed Aug. 4, 2017, entitled “METHODFOR MANUFACTURING A LOW-PROFILE INTERCRANIAL DEVICE AND THE LOW-PROFILEINTERCRANIAL DEVICE MANUFACTURED THEREBY” (published as U.S. PatentApplication Publication No. 2018/0055640), which claims the benefit ofU.S. Provisional Patent Application 62/381,242, filed Aug. 30, 2016,entitled “METHOD FOR MANUFACTURING A LOW-PROFILE INTERCRANIAL DEVICE ANDTHE LOW-PROFILE INTERCRANIAL DEVICE MANUFACTURED THEREBY,” all of whichare incorporated herein by reference. Further details can be found inthe landmark publication by Dr. Gordon and team entitled, “FirstIn-human Experience with Complete Integration of Neuromodulation DeviceWithin a Customized Cranial Implant.” (Operative Neurosurgery 2017).

Also, computer-assisted and/or surgical methods may be integrated withthe use of the clear craniofacial implant as described above. Thecomputer-assisted robot-assisted surgery system may provide a userenhanced implant reconstruction experience, for example, providing asurgeon unprecedented, immediate visual feedback and allowingsingle-stage cranioplasty and all related craniomaxillofacialreconstruction for scenarios related to skull neoplasms, etc.—insituations where the tumor defect is not known beforehand, but where aclear custom implant is needed requiring on-table modification viacomputer-assisted and/or robot-assisted surgery system guidance. Suchguidance is preferably achieved using techniques disclosed in U.S.Patent Application Publication No. 2017/0000505, entitled“Computer-Assisted Craniomaxillofacial Surgery,” which is incorporatedherein by reference. The previously described computer-assistedmodality, together with the newfound “clear” implant advantages, may actsynergistically moving forward for improved outcomes. Even though thecomputer-assisted and/or robot-assisted system may provide the guidanceas to where modification should occur, the “clear” implant with completetransparency will help the surgeon confirm the efficacy of thecomputer-assisted and/or robot-assisted system by seeing the skull edgesunderneath when placed in-situ.

FIGS. 2A-2F, 3A, and 3B illustrate together a representative of thepresent method for single-stage cranioplasty reconstruction using aclear craniofacial implant 10 and the final result with the embeddedfinal clear craniofacial implant 10′. After generating computer-readablereconstruction of a patient's anatomy, preselecting a resection area onthe model, determining implant dimensions (can be a few millimetersgreater than the size of the cranial, craniofacial, and/or facialdefect), and prefabricating the custom craniofacial implant 10 basedupon information generated by known computer-assisted and/orrobot-assisted surgical systems, the surgical procedure is initiatedwith the resection of the skull 106, which leaves behind an anatomicalfeature of interest, such as a cranial, craniofacial, and/or facialdefect 100 with varying thickness which is not consistently smooth dueto the manual cutting aspect with craniotomy by a neurosurgery.

Thereafter, the prefabricated clear custom cranio facial implant 10 isaligned with the unique anatomical features along the periphery 108 ofthe cranial, craniofacial, and/or facial defect 100 and theprefabricated clear custom craniofacial implant 10 is positioned overthe cranial, craniofacial, and/or facial defect 100. The boundaries 108of the cranial, craniofacial, and/or facial defect 100 are then tracedon the prefabricated clear custom cranio facial implant 10 in the formof the tracing cut lines 12 and the prefabricated clear customcraniofacial implant 10 is trimmed in accordance with the tracing cutlines 12 to create the final clear craniofacial implant 10′. Cutting(that is, the cutting of the cranio facial implant 10 to achieve atrimmed craniofacial implant 10 of a desired size and shape) is achievedin a conventional manner using various cutting, sanding and processingmachines known to those skilled in the art. It is appreciated that suchcutting may include non-manual techniques, for example, as might beperformed with computer controlled robotic systems, such as thosedescribed by Dr. Gordon's team in U.S. Patent Application PublicationNo. 2017/0252169, entitled “A Cutting Machine for Resizing New ImplantsDuring Surgery,” which is incorporated herein by reference. The resultof such a single-stage cranioplasty reconstruction according to anembodiment is shown in FIG. 3B with the final clear cranio facialimplant 10′ attached to the patient's anatomy and showing an exact fitwith the absence of gaps along the periphery of the “implant-cranialbone interface.” However, future methods for clear implant sizemodification may include computer-assistance and/or robot-assistance asdisclosed in U.S. Patent Application Publication No. 2017/0000505,entitled “Computer-Assisted Craniomaxillofacial Surgery.”

Further to the clear craniofacial implant described above, it isappreciated the clear craniofacial implant may be modified in a manneradding even greater functionality without detracting from the ability ofa surgeon to advantageously employ the trace lines and cutting describedabove to achieve an optimal fit. For example, and with reference to FIG.4, clear craniofacial implant 10 may be provided with laser etching(s)or dyed marking(s) 30 indicating the desired implanted orientation ofthe clear craniofacial implant (that is, ventral, dorsal, left/rightlateral) relative to the patient anatomy, or patient specific landmarks.Such etching(s) or marking(s) may be in the form of a compass-shape,diamond, a triangle, a straight-line or any other marking that would bereadily understood and identified by a surgeon. The etching(s) ormarking(s) could be adapted to a predetermined part of the anatomy,i.e., nasal bone, a suture intersection, etc., wherein the specificanatomy would be determined during the planning stages of the surgicalprocedure. It is also appreciated etching(s) or marking(s) could be usedto identify anatomy beneath the defect, a tumor sight, an aneurysmlocation, planned integration of other neurological devices, or afunctional component (for example, seizure focus, enlarged ventriclewith hydrocephalus, shunts, catheters, leads, pumps, drips, flow, etc.),as well as the orientation of such a functional component. For example,the etching(s) or marking(s) could be used in the identification ofseizure focus, enlarged ventricle with hydrocephalus, shunts, catheters,leads, pumps, drips, flow, etc. Still further, the etching(s) ormarking(s) may be employed on the clear craniofacial implant to identifyprescriptions, disease state, date of surgery, type of neurotechnologyhoused within the implant, etc. It is also appreciated such etching(s)or marking(s) could be used in various combinations to achieve variousgoals at one time.

It should be appreciated that while both the neurological device(s) 20and the various etching(s) or marking(s) 30 are shown in FIG. 4 on asingle craniofacial implant 10, various combinations of neurologicaldevice(s) 20 and/or etching(s)/marking(s) 30 may be used in accordancewith the present invention.

Considering the integration of both the neurological device(s) 20 andthe various etching(s) or marking(s) 30 into the craniofacial implant 10in accordance with the present invention, it is contemplated suchcraniofacial implants may be manufactured in various manners to achieveoptimal fit and functionality. In accordance with one embodiment, theneurological device(s) 20 and the various etching(s) or marking(s) 30are integrated into the body of the craniofacial implant through the useof barium sulfite integrated into craniofacial implants composed ofPMMA. In accordance with another embodiment, neurological device(s) 20and the various etching(s) or marking(s) 30 are integrated into thecraniofacial implant 10, for example, through the application of 3Dprinting (additive manufacturing) techniques with layers or specificareas of radiographic elements or markings incorporated into thestructure of the craniofacial implant 10. In accordance with otherembodiments, the craniofacial implant 10 may be manufactured through theapplication of 3D printing, wherein specific shapes adapted for cranialrestoration and augmentation are incorporated into the craniofacialimplant 10; including, but not limited to, augmentation optimized forthe integration of neurological device(s) 20, the provision ofetching(s) or marking(s) 30, and/or the surgical integration of othercomplementary devices. Liquid molding may also be employed, wherein theliquid molding techniques are used to create specific shapes adapted forcranial restoration and augmentation; including, but not limited to,augmentation optimized for the integration of neurological device(s) 20,the provision of etching(s) or marking(s) 30, and/or the surgicalintegration of other complementary devices. Still further vacuumassisted liquid molding may be employed, wherein vacuum assisted liquidmolding techniques are used to create specific shapes adapted forcranial restoration and augmentation; including, but not limited to,augmentation optimized for the integration of neurological device(s) 20,the provision of etching(s) or marking(s) 30, and/or the surgicalintegration of other complementary devices. Mechanically alteredmanufacturing methods combining molding, liquid molding, 3D printing mayalso be used in creating craniofacial implants 10 with specific shapesadapted for cranial restoration and augmentation; including, but notlimited to, augmentation optimized for the integration of neurologicaldevice(s) 20, the provision of etching(s) or marking(s) 30, and/or thesurgical integration of other complementary devices via CNC (ComputerNumerical Control) machining, laser, robot, robotic laser. Suchcraniofacial implants 10 could also be manufactured using millingtechniques, wherein blocks of an implant material are milled via CNCmachines, laser, robot, and/or robotic laser to create specific shapesadapted for cranial restoration and augmentation; including, but notlimited to, augmentation optimized for the integration of neurologicaldevice(s) 20, the provision of etching(s) or marking(s) 30, and/or thesurgical integration of other complementary devices.

The described methods of the embodiments may be utilized during asurgical procedure, such as a surgical implantation procedure forvarious forms of craniomaxillo facial surgery and/or neurosurgeryincluding an implant-based cranioplasty. Accordingly, the implant may bea custom, clear craniofacial implant made of either alloplasticbiomaterials or biologic tissue engineered cells as described above anda being, such as a human being, on whom the surgical procedure isperformed. In other words, the clear craniofacial implant ismaterial-agnostic and only requires complete translucency and opticalclarity.

The method described above overcomes the deficiencies of the prior artby providing a method that reduces inaccuracies; in particular,performance, stability, simplicity, environmental benefit, cost, etc.When using an opaque implant or bone graft for reconstruction, as usedin the prior art, a template may be used to represent the size and shapeof the cranial, craniofacial, and/or facial defect—usually paper orcloth from other sterile product in the operating room. When translatingthe template to the implant orientation changes (anterior, posterior,medial, lateral, superior, inferior, or rotational) occur and thepotential for infection and positional rotation increases. Furthermore,the “opaque” nature of the implant prevents the surgeon from seeing theunderlying brain and/skull underneath in relation for size assessment,Dural pulsations symbolizing normal brain function, and/or surgicalbleeding. These disadvantages have been described and published by theinventor in Gordon C R, et al., “Discussion of Usefulness of anOsteotomy Template for Skull Tumorectomy and Simultaneous SkullReconstruction,” The Journal of Craniofacial Surgery, Vol. 27, No. 6,September 2016. Simultaneously each skull or bony skeleton has uniqueanatomy that implants and/or grafts are contoured to match specifically.The result is that using templates to translate the cranial,craniofacial, and/or facial defect to an “opaque” implant losesorientation and the implant and/or graft does not fit correctly, eitherthe contours don't match with the native skull or the shape is incorrectand requires additional modification. If not using a template, thesurgeon is just “eyeballing” the size and shape of the cranial bonedefect which requires even more rounds of modification and inferior fit.More importantly, oncological principles are being ignored when using acutting template.

The ability to directly match up the cranial, craniofacial, and/orfacial defect and the implant by using “optically clear” implants forthe very first time, in accordance with the present invention, improvesorientation and decreases rounds of modification and enhances onevisibility as related to brain or bone bleeding underneath. In addition,because the present method employs a “clear implant” and/or graft—whichcan be held uniquely over the cranial, craniofacial, and/or facialdefect created during surgery—the new size and shape of the cranial,craniofacial, and/or facial defect is more accurately translated to theimplant and/or graft; for example, holding the implant over the cranial,craniofacial, and/or facial defect and tracing the cranial,craniofacial, and/or facial defect with a sterile marker. Because theperimeter of the implant rests on the patient's native craniofacialskeleton in the margin between the cranial, craniofacial, and/or facialdefect and the edges of the over-sized clear implant, the orientation ofthe native skull is translated to the implant in a way that waspreviously impossible when transferring a template from the patient tothe current-day implants, which are all “opaque” and provide zerotransparency.

In addition to inaccuracy issues, the more accurately the cranial,craniofacial, and/or facial defect can be translated to theimplant/graft, the less rounds of modification are required to get animplant/graft to an acceptable size and contour, thereby equating toshortened operative times and minimizing risks for infection andsterility. In fact, traditional methods have demonstrated the need forup to 80 minutes by the inventor Dr. Chad R. Gordon (see Berli J U, etal., “Immediate Single-Stage Cranioplasty Following Calvarial Resectionfor Benign and Malignant Skull Neoplasms Using Customized CraniofacialImplants,” The Journal of Craniofacial Surgery, Vol. 26, No. 5,September 2015). By utilizing the clear custom implant described herein,the operative time can be cut down substantially with improved accuracyfor direct translation of cranial, craniofacial, and/or facial defect toimplant/graft with much improved speed and efficiency.

Still further, operating rooms average a cost of $62/minute notincluding anesthesia, salaries, and some other costs (Shippert, R. AStudy of Time-Dependent Operating Room Fees and How to Save $100,000 byUsing Time-Saving Products. Am J. of Cosmetic Surgery, Vol. 22, No. 1,2005. Available online July 2013. Macario, A. What does One Minute ofOperating Room Time Cost? J. of Clinical Anesthesia, Vol. 22, 2010.Available online July 2013). Shortening surgery by use of a novel clearimplant saves money in this setting as well as significant labor.

Ultimately, and considering accuracy is improved, the ideal contour andreconstruction sought by the surgeon and the patient are more achievablewith clear implants in single-stage cranioplasty unlike ever before.Further still, it is appreciated the concepts underlying the presentinvention may be applied to multi-stage cranioplasties, with or withouta neurological device being integrated into the clear craniofacialimplant. Additionally, the “optical clear” advantage allows unimpededtransmittance of ultrasound and/or wireless ECOG transmission, asreported by Gordon et al. in “First In-human Experience with CompleteIntegration of Neuromodulation Device Within a Customized CranialImplant” as discussed above.

While the preferred embodiments have been shown and described, it willbe understood that there is no intent to limit the invention by suchdisclosure, but rather, it is intended to cover all modifications andalternate constructions falling within the spirit and scope of theinvention.

The invention claimed is:
 1. A method for performing a cranioplasty,comprising: creating a cranial, craniofacial, and/or facial defect;positioning a clear craniofacial implant over the cranial, craniofacial,and/or facial defect; tracing cut lines defining a boundary of thecranial, craniofacial, and/or facial defect on the clear craniofacialimplant, the implant fabricated based upon information generated bypreoperative scans, wherein the step of positioning the clearcraniofacial implant over the cranial, craniofacial, and/or facialdefect is performed prior to the step of tracing cut lines and the stepof tracing cut lines includes tracing cut lines on the clearcraniofacial implant as the clear craniofacial implant lies over thecranial, craniofacial, and/or facial defect, wherein a boundary of thecranial, craniofacial, and/or facial defect is viewable through theclear craniofacial implant thereby allowing for visible tracing; cuttingthe clear custom craniofacial implant along the traced cut lines foroptimal fit of the craniofacial implant along the cranial, craniofacial,and/or facial defect; and attaching the final clear craniofacial implantto the cranial, craniofacial, and/or facial defect.
 2. The methodaccording to claim 1, wherein the clear craniofacial implant is composedof PMMA.
 3. The method according to claim 1, wherein the step ofpositioning includes placing the clear craniofacial implant over thecranial, craniofacial, and/or facial defect in a desired orientationbased upon a unique anatomy of an outer surface of a skull surroundingthe cranial, craniofacial, and/or facial defect.
 4. The method accordingto claim 1, wherein the step of tracing includes tracing a periphery ofthe cranial, craniofacial, and/or facial defect directly onto the clearcraniofacial implant using a sterile intra-operative marking pen.
 5. Themethod according to claim 1, wherein the step of positioning includesplacing the clear craniofacial implant over the cranial, craniofacial,and/or facial defect in a desired orientation based upon a uniqueanatomy of an outer surface of a skull surrounding the cranial,craniofacial, and/or facial defect which is visible through the clearcraniofacial implant.
 6. The method according to claim 5, wherein thestep of cutting includes trimming the clear craniofacial implant usingmedical grade tools, computer-assisted and/or robot-assisted devices inan operating room along boundaries defined by the traced cut lines. 7.The method according to claim 1, wherein the step of cutting includestrimming the clear craniofacial implant using medical grade tools,computer-assisted and/or robot-assisted devices in an operating roomalong boundaries defined by the traced cut lines.
 8. The methodaccording to claim 1, further including the steps of identifying adiseased portion associated with aberrant craniofacial and/or brainanatomy and generating a computer-readable reconstruction of a patient'sanatomy associated with the diseased portion for the purpose ofdesigning and fabricating the clear craniofacial implant.
 9. The methodaccording to claim 8, wherein the step of creating a cranial,craniofacial, and/or facial defect includes cutting out a diseasedportion of a skull to be replaced with the clear craniofacial implant.10. The method according to claim 5, wherein the step of creating acranial, craniofacial, and/or facial defect includes cutting out aportion of a skull to be replaced with the clear craniofacial implant.11. The method according to claim 5, wherein a neurological device withconstant or intermittent function is incorporated within the clearcraniofacial implant.
 12. The method according to claim 11, furtherincluding the step of prefabricating the clear craniofacial implant,wherein prefabricating the clear craniofacial implant includesincorporating the neurological device within the clear craniofacialimplant via 3D printing, liquid molding, vacuum assisted liquid molding,mechanically altered manufacturing methods, milling techniques, orcombination thereof.
 13. The method according to claim 11, wherein theneurological device is a monitoring device or device for treating aneurological disorder.
 14. The method according to claim 5, wherein thecranioplasty is a single-stage cranioplasty.
 15. The method according toclaim 5, wherein the clear craniofacial implant includes an etching or amarking.
 16. The method according to claim 15, further including thestep of prefabricating the clear craniofacial implant, whereinprefabricating the clear craniofacial implant includes incorporating theetching or the marking via 3D printing, liquid molding, vacuum assistedliquid molding, mechanically altered manufacturing methods, millingtechniques, or combination thereof.
 17. The method according to claim15, wherein the etching or marking indicates a desired implantedorientation of the clear craniofacial implant.
 18. The method accordingto claim 15, wherein the etching or marking identifies anatomy beneaththe defect, a tumor sight, an aneurysm location, or a functionalcomponent.
 19. The method according to claim 15, wherein the etching ormarking identifies a prescription, a disease state, or a date ofsurgery, or type of implantable neurotechnology housed within the clearcraniofacial implant.
 20. The method according to claim 1, wherein theclear craniofacial implant is sonolucent.
 21. The method according toclaim 1, wherein the clear craniofacial implant is radiolucent.
 22. Amethod for using a craniofacial implant, comprising: creating a cranial,craniofacial, and/or facial defect; positioning a clear craniofacialimplant over the cranial, craniofacial, and/or facial defect; tracingcut lines defining a boundary of the cranial, craniofacial, and/orfacial defect on the clear craniofacial implant, the implantprefabricated based upon information generated by preoperative scans,wherein the step of positioning the clear craniofacial implant over thecranial, craniofacial, and/or facial defect is performed prior to thestep of tracing cut lines and the step of tracing cut lines includestracing cut lines on the clear craniofacial implant as the clearcraniofacial implant lies over the cranial, craniofacial, and/or facialdefect, wherein a boundary of the cranial, craniofacial, and/or facialdefect is viewable through the clear craniofacial implant therebyallowing for visible tracing; and cutting the clear custom craniofacialimplant along the traced cut lines for optimal fit of the craniofacialimplant along the cranial, craniofacial, and/or facial defect.
 23. Themethod according to claim 22, wherein the clear craniofacial implant iscomposed of PMMA.
 24. The method according to claim 22, wherein aneurological device with constant or intermittent function isincorporated within the clear craniofacial implant.
 25. The methodaccording to claim 24, further including the step of prefabricating theclear craniofacial implant, wherein prefabricating the clearcraniofacial implant includes incorporating the neurological devicewithin the clear craniofacial implant via 3D printing, liquid molding,vacuum assisted liquid molding, mechanically altered manufacturingmethods, milling techniques, or combination thereof.
 26. The methodaccording to claim 24, wherein the neurological device is a monitoringdevice or device for treating a neurological disorder.
 27. The methodaccording to claim 22, wherein the clear craniofacial implant includesan etching or a marking.
 28. The method according to claim 27, furtherincluding the step of prefabricating the clear craniofacial implant,wherein prefabricating the clear craniofacial implant includesincorporating the etching or the marking via 3D printing, liquidmolding, vacuum assisted liquid molding, mechanically alteredmanufacturing methods, milling techniques, or combination thereof. 29.The method according to claim 27, wherein the etching or markingindicates a desired implanted orientation of the clear craniofacialimplant.
 30. The method according to claim 27, wherein the etching ormarking identifies anatomy beneath the defect, a tumor sight, ananeurysm location, or a functional component.
 31. The method accordingto claim 27, wherein the etching or marking identifies a prescription, adisease state, or a date of surgery, or type of implantableneurotechnology housed within the clear craniofacial implant.
 32. Themethod according to claim 22, wherein the clear craniofacial implant issonolucent.
 33. The method according to claim 22, wherein the clearcraniofacial implant is radiolucent.